BackgroundGlobally, inequality between men and women manifests in a variety of ways. In particular, gender inequality increases the risk of perpetration of violence against women (VAW), especially intimate partner violence (IPV), by males. The World Health Organization (WHO) estimates that 35 % of women have experienced physical, psychological and/or sexual IPV at least once in their lives, making IPV unacceptably common. In 2006, the Maria da Penha Law on Domestic and Family Violence, became the first federal law to regulate VAW and punish perpetrators in Brazil. This study examines the relationship between Brazilian VAW legislation and male perpetration of VAW by comparing reported prevalence of IPV before and after the enactment of the Maria da Penha Law.MethodsTo assess changes in magnitude of IPV before and after the law, we used data from the 2013 Brazilian National Health Survey; we replicated the analyses conducted for the WHO Multi-Country Study on Women’s Health and Domestic Violence Against Women-whose data were collected before the passage of the Maria da Penha Law. We compare findings from the two studies.ResultsOur analyses show an increase in the reported prevalence of physical violence, and a decrease in the reported prevalence of sexual and psychological violence. The increase may result from an actual increase in physical violence, increased awareness and reporting of physical violence, or a combination of both factors. Additionally, our analysis revealed that in the urban setting of São Paulo, physical violence was more likely to be severe and occur in the home; meanwhile, in the rural state of Pernambuco, physical violence was more likely to be moderate in nature and occur in public.ConclusionThe Maria da Penha Law increased attention and resources for VAW response and prevention; however, its true impact remains unmeasured. Our data suggest a need for regular, systematic collection of comparable population-based data to accurately estimate the true prevalence of IPV in Brazil. Furthermore, such data may inform policy and program planning to address specific needs across diverse settings including rural and urban communities. If routinely collected over time, such data can be used to develop policies and programs that address all forms of IPV, as well as evidence-based programs that address the social and cultural norms that support other forms of VAW and gender inequality.